The devices of the above-cited type are particularly known and used in the context of regulating the flow of fluid (flow rate, distribution, orientation) to transmit, with gear reduction, a torque or a movement between an active means of actuation (input shaft; electric, pneumatic, hydraulic actuator) and at least one regulating and/or distribution element such as a valve or the like, which is optionally multi-path.
These regulating elements generally exhibit a state or a safety position corresponding to an adjustment of the flow rate or a distribution configuration of the element protecting the components, modules, circuits or the like that are fed or traversed by the fluid concerned.
Various devices able and designed to avoid an abnormal configuration or positioning, or to force the regulating element into a safety position, are already known and used.
Thus, actuators are known that integrate or are directly associated with elastic means that act on the drive shaft of the actuator to bring it or to bring it back by default to an initial position.
Also, means of the return spring type are known that are able and designed to act on an intermediate component of a drive train for transmitting movement between an actuator and an actuated element, to bring back the latter automatically into a safety position when certain conditions are validated or are no longer validated, or when a malfunction or an abnormal situation is identified. The documents FR 2 839 164 and FR 2 901 005, for example, disclose such solutions.
However, in the above-cited known solutions, the elastic or spring means must be able to supply a return torque or a force that is sufficient to drive not only the element with which it is associated, but also all of the components of the drive train and the actuator. The result of this is a high cost for the production of this safety function and therefore the necessity either of oversizing the actuator considerably to overcome, in normal operation, the unwanted action (reverse bias) of the return means constantly, or of providing an additional retaining means in normal operation and of conditional release of said return means, driving a structural complexity and a more considerable bulk.